Business Insider spoke to Evelyn Dorkel, a London-based registered dietitian with over 12 years of experience, who talked us through the low FODMAP diet that restricts a surprisingly wide range of foods — and she says around 70% of people feel better after following it.

Dorkel works with time-poor city dwellers at firms like Deloitte, Bank of America Merrill Lynch, and Goldman Sachs, to help them improve their eating habits. She recently created a Mediterranean menu that caters to gluten-intolerant, low FODMAP, and dairy-free diets at co-working space JOVA in Central London.

Dorkel told Business Insider that one of the things clients come to her most with are digestive issues associated to IBS, such as bloating, excessive wind, abdominal pain, and diarrhoea or constipation.

To these clients she often recommends the low FODMAP diet which focuses on the reduction of certain fermentable carbohydrates.

This "Quinoa Greek Salad" is an alternative to the usual lunchtime sandwiches for those following the low FODMAP diet. JOVA

FODMAP stands for Fermentable, Oligo-, Di-, Mono-saccharides and Polyols. They are essentially carbohydrates that the body's small intestine struggles to digest and are found in wheat, barley, garlic, onion, beans, and lentils, as well as certain fruit and vegetables.

The low FODMAP diet was established in Australia several years ago. Research in this field has since confirmed the benefits and specialists treating patients with IBS now often recommend a trial of a low FODMAP diet to manage symptoms, Dorkel said.

It has since gained traction in the UK. It was adapted by researchers at King's College London and implemented at Guy's and St Thomas' NHS Trust in London.

How to follow the low FODMAP diet

First off Dorkel stressed the importance of discussing a low FODMAP diet with a dietitian to avoid misdiagnosis, nutritional deficiencies, and frustration.

"Improvement of symptoms is unlikely to occur if not followed correctly," she said, adding that there is a lot of misinformation on this topic out there.

Patients following the diet will first cut out certain high FODMAP foods. Dorkel said this typically needs to be followed, and strictly, for a month to six weeks to see any improvement. King's College suggests patients avoid these foods for up to eight weeks.

If patients have seen some improvement after following this diet, they will next gradually begin to reintroduce high FODMAP foods to work out where (and with which foods) their intolerance lie.

Once they've identified the food triggers of their symptoms, patients are encouraged to tailor their normal diet so that they only avoid the food causing the unwanted symptoms.

Coconut porridge with blueberry jam is a low FODMAP breakfast options served at JOVA. JOVA

Which foods are high FODMAP?

The low FODMAP diet is considered by some to be an awkward one to follow because of the types of foods you must avoid while following it.

For example, because wheat is a high FODMAP food item, lunchtime sandwiches are strictly off the menu, and avoiding garlic and onion, ingredients found in most marinades and sauces, can make dining out at restaurants difficult.

Some high FODMAP fruits and vegetables are pretty surprising, too. Apples, pears, leeks, mushrooms, watermelon, and asparagus are all high FODMAP foods to be avoided. People following the diet may also need to reduce their lactose intake, Dorkel explained.

As for what you can eat, here are some of the types of low FODMAP recipes that Dorkel came up with for Jova's menu, that could be adapted for anyone wishing to give the diet a go: